Eye to Brain
Packed densely in the fovea, these photoreceptors interact with ganglion cells in a one-to-one mapping and preserve color information.
What are cones?
The ventral visual stream projects to the inferior temporal cortex, is specialized for object recognition, and is commonly referred to by this informal name.
What is the "What" pathway?
In a sound wave, amplitude dictates how loud a sound is, while frequency determines this specific perceptual quality.
What is pitch?
Movement direction in M1 is not encoded by single, narrowly tuned neurons, but rather by the collective activity of many neurons, a concept known as this.
What is a population vector?
This basal ganglia loop facilitates movement by exciting the thalamus and cortex, and is boosted by dopamine acting on D1 receptors.
What is the direct pathway?
Because many of them feed into a single ganglion cell, these photoreceptors are highly sensitive to small amounts of light but less detailed.
What are rods?
Also known as area V5, this extrastriate area contains direction-selective neurons that are critical for visual motion processing.
What is area MT?
These sensory receptors receive input from fluid vibrations in the cochlea and transduce it into electrical signals via spiral ganglion cells.
What are cilia (or hair cells)?
Located dorsomedially in Brodmann Area 6, this motor region is strongly associated with planning self-initiated voluntary movements and complex sequences.
What is the Supplementary Motor Area (SMA)?
Parkinson's disease is a hypokinetic disorder characterized by decreased excitation from the direct pathway and increased suppression from this basal ganglia loop.
What is the indirect pathway?
Found in V1, these specific cells respond best to bars of light of different orientations, while complex cells care less about the line's exact location.
What are simple cells?
This highly specialized object recognition area in the ventral stream responds strongly to human faces (and can become sensitive to "Greebles" after training).
What is the Fusiform Face Area (FFA)?
Receiving bifurcated inputs from the ventral cochlear nucleus, this brainstem structure is responsible for the initial stage of binaural sound localization.
What is the superior olive?
This lateral portion of Area 6 is thought to be involved in planning actions that are triggered by external cues, such as a visual instruction stimulus.
What is the Premotor Area (PMA)?
Located posterior to the brainstem, this structure relies on an "efference copy" to act as an internal "forward model" for error-driven motor learning.
What is the cerebellum?
Visual information in the geniculostriate pathway travels through the optic nerve and passes through this thalamic nucleus before reaching V1.
What is the lateral geniculate nucleus (LGN)?
The dorsal stream projects to this lobe of the brain and is often referred to as the "Where" or "How" pathway because it transforms visual input for motor planning.
What is the posterior parietal lobe (or cortex)?
Instead of mapping space, the cochlea organizes sound frequencies—from high to low—using this specific type of layout.
What is a tonotopic map?
Wilder Penfield's stimulation work revealed that M1 contains this type of map, where larger cortical representations correspond to body parts requiring finer motor control.
What is a somatotopic map (or motor homunculus)?
Bypassing the striatum, this specific basal ganglia pathway sends direct input from the inferior frontal gyrus (IFG) to the subthalamic nucleus (STN) to rapidly cancel unwanted movements.
What is the hyperdirect pathway?
This faster, phylogenetically older visual pathway projects from the superior colliculus to the pulvinar, making it highly sensitive to motion in the periphery.
What is the tectopulvinar pathway?
Patient DF suffered from visual form agnosia due to ventral stream lesions, leaving her unable to consciously perceive orientation, but perfectly able to do this task accurately.
What is grasping (or hand orientation matching)?
After leaving the inferior colliculus in the midbrain, auditory signals travel to this specific thalamic nucleus before projecting to the primary auditory cortex.
What is the medial geniculate nucleus (MGN)?
Prefrontal cortex encodes abstract, higher-level goals to help guide our actions. PFC damage can cause this symptom associated with an inability to inhibit or stop unwanted goals from being acted upon.
What is utilization behavior (could also accepted impulsivity)?
Unlike Parkinson's disease, this hyperkinetic disorder is caused by a decreased effect of the indirect pathway, leading to unwanted, excessive movements.
What is Huntington's Disease?